I m using TSQL, I want to extract text from the string and save it as two column and third one as
The following code is not complete but just getting rid of PRD1T_ the Finapp and not sure how to cater for rest of the text
Select substring(Table_name,
charindex('_',Table_name)+1,
Len(Table_name) - charindex('.',Table_name)) as Landing_Schema_Name
FROM [e].[Load_History_test]
When asking questions like this it is best to provide some sample data and expected results, as Ronen suggested. For SQL questions a really good way of doing this is with a temp table and sample data, like this:
CREATE TABLE #load_history_test (
table_name VARCHAR(100)
);
INSERT INTO #load_history_test
SELECT 'PRD1T_FINAPP.HOLCONTRACT'
UNION ALL
SELECT 'PRD1T_FINAPP.TOCCASE'
UNION ALL
SELECT 'PRD1T_FINAPP.TOCCASE';
So that provides something people can run and starts towards the criteria for a minimal, reproducible example, which is the secret to getting a good answer on StackOverflow. I have used SELECT with UNION ALL as Azure Synapse does not currently support the VALUES clause for multiple records.
For expected results, it's often good to display them in a table, something like this:
col1
col2
col3
PRD1T
FINAPP
HOLCONTRACT
PRD1T
FINAPP
TOCCASE
This way it's clear to people what you expect. It is not clear why you have two TOCCASE examples in your screenprint.
For your problem, there is more than one approach. You are along the right lines with CHARINDEX, SUBSTRING and LEFT but things can start to look complicated. Therefore I tend to wrap up some complexity in a Common Table Expression (CTE), see below for an example. There is also a kind of 'trick' approach with a built-in SQL function called PARSENAME. This is designed to extract from four-part object names common in SQL Server eg <server-name>.<database-name>.<schema-name>.<object-name>. As long as your object names will never have more than four parts, this approach will work for you. See the main help for PARSENAME here. See below for a complete demo that runs end to end with a temp table to demonstrate the different principles:
IF OBJECT_ID('#load_history_test') IS NOT NULL
DROP TABLE #load_history_test;
CREATE TABLE #load_history_test (
table_name VARCHAR(100)
);
INSERT INTO #load_history_test
SELECT 'PRD1T_FINAPP.HOLCONTRACT'
UNION ALL
SELECT 'PRD1T_FINAPP.TOCCASE'
UNION ALL
SELECT 'PRD1T_FINAPP.TOCCASE';
;WITH cte AS (
SELECT
table_name AS original_table_name,
CHARINDEX( '_', table_name ) underscorePos,
CHARINDEX( '.', table_name ) stopPos,
REPLACE( table_name, '_', '.' ) AS clean_table_name
FROM #load_history_test
)
SELECT
*,
PARSENAME( clean_table_name, 3 ) a,
PARSENAME( clean_table_name, 2 ) b,
PARSENAME( clean_table_name, 1 ) c,
LEFT( original_table_name, underscorePos - 1 ) getItemBeforeUnderscore,
SUBSTRING( original_table_name, underscorePos + 1, ( ( stopPos - 1 ) - underscorePos ) ) AS getItemAfterUnderscore,
SUBSTRING( original_table_name, stopPos + 1, 99 ) getItemAfterStop
FROM cte;
I have two columns, COL1 and COL2. COL1 has value like 'Birds sitting on $1 and enjoying' and COL2 has value like 'the.location_value[/tree,\building]'
I need to update third column COL3 with values like 'Birds sitting on /tree and enjoying'
i.e. $1 in 1st column is replaced with /tree
which is the 1st word from list of comma separated words with in square brackets [] in COL2 i.e. [/tree,\building]
I wanted to know the best suitable combination of string function in postgresql to use to achieve this.
You need to first extract the first element from the comma separated list, to do that, you can use split_part() but you first need to extract the actual list of values. This can be done using substring() with a regular expression:
substring(col2 from '\[(.*)\]')
will return /tree,\building
So the complete query would be:
select replace(col1, '$1', split_part(substring(col2 from '\[(.*)\]'), ',', 1))
from the_table;
Online example: http://rextester.com/CMFZMP1728
This one should work with any (int) number after $:
select t.*, c.col3
from t,
lateral (select string_agg(case
when o = 1 then s
else (string_to_array((select regexp_matches(t.col2, '\[(.*)\]'))[1], ','))[(select regexp_matches(s, '^\$(\d+)'))[1]::int] || substring(s from '^\$\d+(.*)')
end, '' order by o) col3
from regexp_split_to_table(t.col1, '(?=\$\d+)') with ordinality s(s, o)) c
http://rextester.com/OKZAG54145
Note:it is not the most efficient though. It splits col2's values (in the square brackets) each time for replacing $N.
Update: LATERAL and WITH ORDINALITY is not supported in older versions, but you could try a correlating subquery instead:
select t.*, (select array_to_string(array_agg(case
when s ~ E'^\\$(\\d+)'
then (string_to_array((select regexp_matches(t.col2, E'\\[(.*)\\]'))[1], ','))[(select regexp_matches(s, E'^\\$(\\d+)'))[1]::int] || substring(s from E'^\\$\\d+(.*)')
else s
end), '') col3
from regexp_split_to_table(t.col1, E'(?=\\$\\d+)') s) col3
from t
In a word game similar to Ruzzle or Letterpress, where users have to construct words out of a given set of letters:
I keep my dictionary in a simple SQL table:
create table good_words (
word varchar(16) primary key
);
Since the game duration is very short I do not want to check every entered word by calling a PHP script, which would look that word up in the good_words table.
Instead I'd like to download all possible words by one PHP script call before the round starts - since all letters are known.
My question is: if there is a nice SQLish way to find such words?
I.e. I could run a longer-taking script once to add a column to good_words table, which would have same letters as in the word columnt, but sorted alphabetically... But I still can't think of a way to match for it given a set of letters.
And doing the word matching inside of a PHP script (vs. inside the database) would probably take too long (because of bandwidth: would have to fetch every row from the database to the PHP script).
Any suggestions or insights please?
Using postgresql-8.4.13 with CentOS Linux 6.3.
UPDATE:
Other ideas I have:
Create a constantly running script (cronjob or daemon) which would prefill an SQL table with precompiled letters board and possible words - but still feels like a waste of bandwidth and CPU, I would prefer to solve this inside the database
Add integer columns a, b, ... , z and whenever I store a word into good_words, store the letter occurences there. I wonder if it is possible to create an insert trigger in Pl/PgSQL for that?
Nice question, I upvoted.
What you're up to is a list of all possible permutations of the given letters of a given length. As described in the PostgreSQL wiki, you can create a function and call it like this (matches highlighted letters in your screenshot):
SELECT * FROM permute('{E,R,O,M}'::text[]);
Now, to query the good_words use something like:
SELECT gw.word, gw.stamp
FROM good_words gw
JOIN permute('{E,R,O,M}'::text[]) s(w) ON gw.word=array_to_string(s.w, '');
This could be a start, except that it doesn't check if we have enough letters, only if he have the right letters.
SELECT word from
(select word,generate_series(0,length(word)) as s from good_words) as q
WHERE substring(word,s,1) IN ('t','h','e','l','e','t','t','e','r','s')
GROUP BY word
HAVING count(*)>=length(word);
http://sqlfiddle.com/#!1/2e3a2/3
EDIT:
This query select only the valid words though it seems a bit redundant. It's not perfect but certainly proves it can be done.
WITH words AS
(SELECT word, substring(word,s,1) as sub from
(select word,generate_series(1,length(word)) as s from good_words) as q
WHERE substring(word,s,1) IN ('t','e','s','e','r','e','r','o','r','e','m','a','s','d','s','s'))
SELECT w.word FROM
(
SELECT word,words.sub,count(DISTINCT s) as cnt FROM
(SELECT s, substring(array_to_string(l, ''),s,1) as sub FROM
(SELECT l, generate_subscripts(l,1) as s FROM
(SELECT ARRAY['t','e','s','e','r','e','r','o','r','e','m','a','s','d','s','s'] as l)
as q)
as q) as let JOIN
words ON let.sub=words.sub
GROUP BY words.word,words.sub) as let
JOIN
(select word,sub,count(*) as cnt from words
GROUP BY word, sub)
as w ON let.word=w.word AND let.sub=w.sub AND let.cnt>=w.cnt
GROUP BY w.word
HAVING sum(w.cnt)=length(w.word);
Fiddle with all possible 3+ letters words (485) for that image: http://sqlfiddle.com/#!1/2fc66/1
Fiddle with 699 words out of which 485 are correct: http://sqlfiddle.com/#!1/4f42e/1
Edit 2:
We can use array operators like so to get a list of words that contain the letters we want:
SELECT word as sub from
(select word,generate_series(1,length(word)) as s from good_words) as q
GROUP BY word
HAVING array_agg(substring(word,s,1)) <# ARRAY['t','e','s','e','r','e','r','o','r','e','m','a','s','d','s','s'];
So we can use it to narrow down the list of words we need to check.
WITH words AS
(SELECT word, substring(word,s,1) as sub from
(select word,generate_series(1,length(word)) as s from
(
SELECT word from
(select word,generate_series(1,length(word)) as s from good_words) as q
GROUP BY word
HAVING array_agg(substring(word,s,1)) <# ARRAY['t','e','s','e','r','e','r','o','r','e','m','a','s','d','s','s']
)as q) as q)
SELECT DISTINCT w.word FROM
(
SELECT word,words.sub,count(DISTINCT s) as cnt FROM
(SELECT s, substring(array_to_string(l, ''),s,1) as sub FROM
(SELECT l, generate_subscripts(l,1) as s FROM
(SELECT ARRAY['t','e','s','e','r','e','r','o','r','e','m','a','s','d','s','s'] as l)
as q)
as q) as let JOIN
words ON let.sub=words.sub
GROUP BY words.word,words.sub) as let
JOIN
(select word,sub,count(*) as cnt from words
GROUP BY word, sub)
as w ON let.word=w.word AND let.sub=w.sub AND let.cnt>=w.cnt
GROUP BY w.word
HAVING sum(w.cnt)=length(w.word) ORDER BY w.word;
http://sqlfiddle.com/#!1/4f42e/44
We can use GIN indexes to work on arrays so we probably could create a table that would store the arrays of letters and make words point to it (act, cat and tact would all point to array [a,c,t]) so probably that would speed things up but that's up for testing.
Create a table that has entries (id, char), be n the number of characters you are querying for.
select id, count(char) AS count from chartable where (char = x or char = y or char = z ...) and count = n group by id;
OR (for partial matching)
select id, count(char) AS count from chartable where (char = x or char = y or char = z ...) group by id order by count;
The result of that query has all the word-id's that fit the specifications. Cache the result in a HashSet and simple do a lookup whenever a word is entered.
You can add the column with sorterd letters formatted like '%a%c%t%'. Then use query:
select * from table where 'abcttx' like sorted_letters
to find words that can be built from letters 'abcttx'. I don't know about performance, but simplicity probably can't be beaten :)
Here is a query that finds the answers that can be found by walking through adjacent fields.
with recursive
input as (select '{{"t","e","s","e"},{"r","e","r","o"},{"r","e","m","a"},{"s","d","s","s"}}'::text[] as inp),
dxdy as(select * from (values(-1,-1),(-1,0),(-1,1),(0,1),(0,-1),(1,-1),(1,0),(1,1)) as v(dx, dy)),
start_position as(select * from generate_series(1,4) x, generate_series(1,4) y),
work as(select x,y,inp[y][x] as word from start_position, input
union
select w.x + dx, w.y + dy, w.word || inp[w.y+dy][w.x+dx]
from dxdy cross join input cross join work w
inner join good_words gw on gw.word like w.word || '%'
)
select distinct word from work
where exists(select * from good_words gw where gw.word = work.word)
(other answers don't take this into account).
Sql fiddle link: http://sqlfiddle.com/#!1/013cc/14 (notice You need an index with varchar_pattern_ops for the query to be reasonably fast).
Does not work in 8.4. Probably 9.1+ only. SQL Fidlle
select word
from (
select unnest(string_to_array(word, null)) c, word from good_words
intersect all
select unnest(string_to_array('TESTREROREMASDSS', null)) c, word from good_words
) s
group by word
having
array_agg(c order by c) =
(select array_agg(c order by c) from unnest(string_to_array(word, null)) a(c))
My own solution is to create an insert trigger, which writes letter frequencies into an array column:
create table good_words (
word varchar(16) primary key,
letters integer[26]
);
create or replace function count_letters() returns trigger as $body$
declare
alphabet varchar[];
i integer;
begin
alphabet := regexp_split_to_array('abcdefghijklmnopqrstuvwxyz', '');
new.word := lower(new.word);
for i in 1 .. array_length(alphabet, 1)
loop
-- raise notice '%: %', i, alphabet[i];
new.letters[i] := length(new.word) - length(replace(new.word, alphabet[i], ''));
end loop;
return new;
end;
$body$ language plpgsql;
create trigger count_letters
before insert on good_words
for each row execute procedure count_letters();
Then I generate similar array for the random board string tesereroremasdss
and compare both arrays using the array contains operator #>
Any new ideas or improvements are always welcome!
In short, I am looking for a single recursive query that can perform multiple replaces over one string. I have a notion it can be done, but am failing to wrap my head around it.
Granted, I'd prefer the biz-layer of the application, or even the CLR, to do the replacing, but these are not options in this case.
More specifically, I want to replace the below mess - which is C&P in 8 different stored procedures - with a TVF.
SET #temp = REPLACE(RTRIM(#target), '~', '-')
SET #temp = REPLACE(#temp, '''', '-')
SET #temp = REPLACE(#temp, '!', '-')
SET #temp = REPLACE(#temp, '#', '-')
SET #temp = REPLACE(#temp, '#', '-')
-- 23 additional lines reducted
SET #target = #temp
Here is where I've started:
-- I have a split string TVF called tvf_SplitString that takes a string
-- and a splitter, and returns a table with one row for each element.
-- EDIT: tvf_SplitString returns a two-column table: pos, element, of which
-- pos is simply the row_number of the element.
SELECT REPLACE('A~B!C#D#C!B~A', MM.ELEMENT, '-') TGT
FROM dbo.tvf_SplitString('~-''-!-#-#', '-') MM
Notice I've joined all the offending characters into a single string separated by '-' (knowing that '-' will never be one of the offending characters), which is then split. The result from this query looks like:
TGT
------------
A-B!C#D#C!B-A
A~B!C#D#C!B~A
A~B-C#D#C-B~A
A~B!C-D-C!B~A
A~B!C#D#C!B~A
So, the replace clearly works, but now I want it to be recursive so I can pull the top 1 and eventually come out with:
TGT
------------
A-B-C-D-C-B-A
Any ideas on how to accomplish this with one query?
EDIT: Well, actual recursion isn't necessary if there's another way. I'm pondering the use of a table of numbers here, too.
You can use this in a scalar function. I use it to remove all control characters from some external input.
SELECT #target = REPLACE(#target, invalidChar, '-')
FROM (VALUES ('~'),(''''),('!'),('#'),('#')) AS T(invalidChar)
I figured it out. I failed to mention that the tvf_SplitString function returns a row number as "pos" (although a subquery assigning row_number could also have worked). With that fact, I could control cross join between the recursive call and the split.
-- the cast to varchar(max) matches the output of the TVF, otherwise error.
-- The iteration counter is joined to the row number value from the split string
-- function to ensure each iteration only replaces on one character.
WITH XX AS (SELECT CAST('A~B!C#D#C!B~A' AS VARCHAR(MAX)) TGT, 1 RN
UNION ALL
SELECT REPLACE(XX.TGT, MM.ELEMENT, '-'), RN + 1 RN
FROM XX, dbo.tvf_SplitString('~-''-!-#-#', '-') MM
WHERE XX.RN = MM.pos)
SELECT TOP 1 XX.TGT
FROM XX
ORDER BY RN DESC
Still, I'm open to other suggestions.